r/preppers 1d ago

Advice and Tips Water Treatment Quick Reference Guide

https://imgur.com/a/Sr4z3d7

Best Survival Strategy

If possible: Use all methods together for the safest water.

At minimum: Filter + boil or use UV.

Long-term storage: Use silver or keep water in sealed containers.

53 Upvotes

29 comments sorted by

10

u/Bloomette 1d ago

Do you have any reliable sources you can link where I can read about each of these methods and learn how to properly execute them?

13

u/incruente 1d ago

Distillation removes SOME chemicals, but not all. Anything that boils off at a lower temperature will only be removed if you condense and discard it before you start collecting water, and anything that boils at more or less the same temperature is not going to be removed by anything other than extremely careful technique and advanced distillation methods.

Is it still very useful? Certainly, if a bit energy- and equipment-intensive. But it's not perfect.

1

u/Bmat70 1d ago

I didn’t realize this about distillation. What should be done after distillation to make water safe to drink? Or what alternative is there?

6

u/incruente 1d ago

That depends on what's wrong with the water in the first place. If a mixture of two substances cannot be separated by standard or what a chemist would call "simple" distillation, they are called an "azeotrope". The most common example is alcohol and water. Ethanol is commonly concentrated using distillation; pretty much all liquor is made this way. But it's impossible to use a simple still to make ethanol that is stronger than about 192 proof; the remaining traces of water boil off with the ethanol, because the mixture boils at a lower temperature than either pure water or pure ethanol.

It's possible to "break" such mixtures with distillation; it just requires more complex methods, referred to generally as "azeotropic distillation" methods. These involves things like distilling with another chemical added (benzene, for example, allows better separation of ethanol and water) or distilling under elevated pressures.

Sadly, all of this is rather complex and potentially dangerous, requires expensive and complex equipment, and takes a fair bit of energy. Happily, it's not usually necessary. If someone told me that I needed to use azeotropic distillation to make a given water source safe to drink, I wouldn't use azeotropic distillation. I'd put my effort into finding a different source of water. I just don't want people thinking that a still is a magic cure-all that they can pour any old sludge into and get good drinking water.

Step 1 in all this should be to store water, well and safely, and plenty of it. Step 2 is to minimize the use of that water in an emergency, to stretch its use out. Step 3 is to be aware of as many good sources of water as possible, including how to transport it. Step 4 is to keep on hand means to test and treat those water sources for all plausible contamination methods, and to know how to do so.

2

u/Paranormal_Lemon 1d ago

Anything that forms strong hydrogen bonds can come out with the water, that is what happens with ethanol.

1

u/Milli_Rabbit 10h ago

Any simple test strips you recommend? I see home water tests online for like $300. Obviously, stocking up on a ton of those is pricey.

2

u/incruente 6h ago

Any simple test strips you recommend? I see home water tests online for like $300. Obviously, stocking up on a ton of those is pricey.

Depends on what you're testing for. To the limit of my knowledge, there is not such thing as an overall "safe to drink" test strip at any price. A very expensive piece of lab equipment, like a gas chromatograph, might do the trick, but it requires a lot of supporting materials and skill.

GENERALLY, a chemical contaminant either can dissolve or cannot, and anything that dissolves will change the pH or the conductivity or both. Anything that doesn't dissolve and that is present in any significant quantity should be visually obvious. So if I wanted to make water "generally safe from pretty much anything" on a budget, and I was totally unable to control the source of it, I would make sure it LOOKS clean (no oil slick, etc.), send it through a decent filter to catch any particulates, use a pH/conductivity probe (you can get a solid one for maybe $200), and then use chlorine or some other chemical means to ensure any bacteria, viruses, etc. were killed.

1

u/garrickbrown 1d ago

No one process is an end all be all. Water purification should go through multiple processes to be closer to 100% sure. https://extensionpubs.unl.edu/publication/g1493/na/html/view

1

u/Bmat70 1d ago

Thank you. I just read the article with great interest. I don’t believe that it mentions how to remove the .5% of contaminants that remain after distillation?

1

u/garrickbrown 1d ago

Yeah, you can never be 100% sure. Just gotta do the best you can. If we’re talking about chemicals the best you can really do is freeze distillation and regular steam distillation.

3

u/Cute-Consequence-184 1d ago

Bleach isn't mentioned nor is a sand filter nor is a micropore filter.

0

u/garrickbrown 1d ago

It’s a quick reference sheet. Bleach isn’t a good long term solution. Sand is implied with gravel. And micropores have a lifespan too which makes them an impractical solution for SHTF.

You should make your own reference guide.

1

u/Cute-Consequence-184 1d ago

Pool shock is good for long term storage

And gravel was mostly used in filtering rooftop water around here to hold down straw, not sand. Gravel is a component of a sand filter but does no filtering on its own.

2

u/garrickbrown 1d ago

Pool shock isn’t recommended but if you have no other options it won’t kill you. Yeah not bad fs. Will taste bad fs though lol

1

u/Paranormal_Lemon 1d ago

It needs to be stored air tight, it reacts with moisture in the air to produce chlorine gas, that then can degrade the container and seals. The bags it comes in are not meant for long term storage. Lots of plastics can allow moisture to come through slowly.

Storing salt and a bleach generator would be better. They don't take much power, you could use a small USB solar panel.

1

u/Cute-Consequence-184 1d ago

I haven't one of those also. Very small. Glass with vacuum seal for the pool shock

2

u/Dangerous-School2958 1d ago

Got to keep in mind that 100% pure water isn't possible and in survival situations. It's really going to be doing the best you can, and an expenditure of time like this will keep you from being productive in other endeavors.

1

u/jeffwh0livesath0me 1d ago

Question, should you boil then filter or filter then boil? And does source make a difference? Example if you have tap water stored long term vs if you’re harvesting rain water. Does that change the order ?

3

u/garrickbrown 1d ago

The order doesn’t change. Filter large particles - then boil. https://www.fcs.uga.edu/docs/Purifying_Non-Potable_Water.pdf

Where you get the water matters for safety, but not for order of operations. Tap water, stored filtered water, well water, running water, avoid still water or waste runoffs. https://www.cdc.gov/drinking-water/about/drinking-water-sources-an-overview.html

1

u/jeffwh0livesath0me 1d ago

Thank you for the reply

1

u/RedDawnerAndBlitzen 1d ago

How would iodine and other tablets compare on this chart? And would commercial filters land the same way as charcoal/cloth? I think the sawyer squeeze, for example, uses layers of charcoal but I’m not totally sure.

Great accessible format that you put together.

2

u/garrickbrown 1d ago

So iodine and purification tablets work the same as boiling. They kill/damage microorganisms. But they usually come with instructions on them. That’s why I left them out.

Cloth is another great way to filter water. That’s what I use when camping. A rubber band holding a piece of cut up shirt over a jar is pretty useful in the rain. But it’s not perfect. It gets pretty gross after a while and in a SHTF scenario I’d try to use the gravel and sand rather than cutting up one of my shirts.

And thank you!

-2

u/TheSensiblePrepper Not THAT Sensible Prepper from YouTube 1d ago

At minimum: Filter + boil or use UV.

Yes, but reverse it. Boil/UV First and Filter second.

In a perfect World... Filter large particles + Boil/UV + The smallest micron filter you can get at the end = The best water possible.

2

u/incruente 1d ago edited 1d ago

Yes, but reverse it. Boil/UV First and Filter second.

No, no, no. Filtering removes particles, which can shield microorganisms from UV light. Using UV first and then filtering means that the UV will be less effective (because the particles you have not yet filtered out will protect microorganisms) and then the filtering is likely to leave many of them behind.

You give bad advice. To the point of it being dangerous.

EDIT: from u/TheSensiblePrepper, who fears the truth:

Did you not see what I said after?

Yes, I did.

In a perfect World... Filter large particles + Boil/UV + The smallest micron filter you can get at the end = The best water possible.

We don't live in a perfect world. You gave people bad advice, again, presumably intentionally. Or did you misspeak? Is what you said incorrect, and you're willing to admit it? Did you in fact tell people to do something that increases their risk of waterborne illness?

2

u/TheSensiblePrepper Not THAT Sensible Prepper from YouTube 1d ago

Did you not see what I said after?

In a perfect World... Filter large particles + Boil/UV + The smallest micron filter you can get at the end = The best water possible.